HTPC with Dothan
GamePC - Dothan Delight : DFI's 855GME-MGF Pentium-M Motherboard and "Tom's Hardware":http://www6.tomshardware.com/motherboard/20041224/pentium_m_boards-07.html. To really build a quiet and cool home theater PC is a challenge. Using the Dothan chipset from Intel is one way to do it. This board from DFI would fit into even a small case or the Silverstone shown previously. The most interestin thing is that a standard 2GHz Pentium M can overclock to 2.8GHz and then blow away just about anything including a Pentium 4 3.6GHz and an Athlon FX-55. So that's the chip to get if you can afford it.
The motherboard is hard to get. From "Canada":http://www.bytewizecomputers.com/products/7/7/689/7240 for aboud CAD$350 so about $300 American. The chip itself is "$430":http://www.pricegrabber.com/search_getprod.php/masterid=2847280/blsrt=1 , so this is an expensive if small option.
You can get it a little cheaper though with the 1.7GHz Pentium M 735 at about "$280":http://www.pricegrabber.com/search_getprod.php/masterid=2837762/blsrt=1 and it will overclock less since it has more like a 17x multiplier compared with 20x for the 2GHz version.